Dental instrument



D A. ZURBRIGG. DENTAL INSTRUMENT. APPLICATION FILED MAVYZILHYHB. RENEWEDSEPT. 17,1920. r 1 382 401. Patented June 21,1921.

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DANIEL ANTON ZURBRIGG, OF MILFORD, DELAVTARE, ASSIG-NOR TO THE L D;GAULK COMPANY, 035 MILFORD, DELA'WARE, A CORPORATION OF DELAWARE DENTALINSTRUMENT.

To all whom it may concern.

Be it known that I, DANIEL ANTON ZUR- BRIGG, a subject of the King ofGreat Britain, residin at Milford, in the count I of Sussex and btate ofDelaware, have invented new and useful Improvements in Dentalinstruments, of which the following is a specification.

This invention relates to improvements in dental instruments of the typeknown as pluggers or packers and which are employed for packing fillingmaterials into tooth cavities. The instruments of the present inventionare specially intended for use in connection with the filling ofposterior teeth, 71. c. molars and bi-cuspids where amalgam or similarmaterial, 2'. 6. material which. is packed into the cavity whileplastic, is employed.

The principal objects of the invention are to secure uniformity in thepacking of the filling material, to avoid or minimize the possibility ofdamage to the cavity wall in connection with the packing of the materialto facilitate the filling operation and to provide for the burnishing ofthe filling in connection with the application thereof.

With the above objects in view the invention is directed more especiallyto the form of the working points or, more strictly, faces of theinstruments and to certain features of combination and arrangementinvolving the said points or faces, all of which will be set forth indetail as the description proceeds.

Instruments in which the invention is incorporated are illustrated inthe accompanying drawings, wherein- Figure l is a perspective view of aninstrument adapted for mesial cavities.

Figs. 2 and 3 are detail side elevations showing the correlative workingpoints at the opposite ends of the instrument.

Fig. 4: is a diagram showing a plan view of a mesial cavity and thelarger working point adapted thereto.

Fig. 5 is a diagram showing the outline of a mesial cavity in themesio-distal dimension and a side elevation of the larger working pointadapted thereto.

Fig. 6 is a perspective View of an instrument adapted for distalcavities.

Figs. 7 and 8 are detail side elevations showing the correlative workingpoints at the opposite ends of the instrument of Fig. 6.

Fig. 9 is a diagram showing a plan view Specification of Letters Patent.

Renewed September Patented June 21, 1921. 17, 1920. Serial No. 410,961.

of a distal cavity and the larger working point adapted thereto.

F 1g. 10 is a diagram showing the outline of a distal cavity in themesio-distal dimen sion and a side elevation of the larger working pointadapted thereto.

Figs. 11 and 12 are diagrams of the correlative packing faces, in twodifferent sizes thereof, of the instruments shown in Figs. 1 to 6respectively.

Similar characters of reference designate corresponding parts throughoutthe several views.

Simple mesio-occlusal (Figs. 4 and 5) or disto-occlusal (Figs. 9 and 10)cavities as prepared for filling are of a general or roughly triangularoutline and have buccolingual and mesio-distal dimensions in theapproximate ratio 4:3. For packing the filling material in such cavitiesT have found that the best results are obtained by the employment ofpacking faces which have the outline of an isosceles trapezoid withtheir surface dimensions in the ratio 4 3. I have also found that forcondensing the filling material into the undercuts and the angles of thematrix with the cavity walls, the best results are obtained by employinga correlative packing face of the same out line, arrangement anddimensional proportions but of considerably reduced area. The form ofthe packing faces is the same for either mesial or distal cavities butfor mesial cavities the longer parallel side of the trapezoid faces anteiorly while for distal cavities it faces posteriorly.

Thus, to obtain the best results, two correlative packing faces shouldbe employed forthe filling of a single cavity, the smaller face beingadapted to condense the material into the undercuts and the angles ofthe matrix with the cavity walls and the larger face being adapted forthe final condensation of the material. It is preferred to provide thetwo correlative packing faces on a single instrument adapted to mesialor distal cavities, as the case may be, Fig. 1 showing an instrumentadapted to mesial cavities and Fig. 6 showing an instrument adapted todistal cavities. Referring to Fig. 1 the larger packing face for finalcondensation is shown at 1 and the smaller correlative packing face isshown at 2, these faces being arranged at opposite ends of theinstrument. Referring to Fig. 6, the larger packing face for finalcondensation is shown at l and the smaller correlative packing face atthe opposite end of the instrument is shownv at 2. For use in bothmesial and distal cavities the packing faces are smooth and plane orflat. Such faces effect a stronger more homogeneous condensation of theamalgam and also produce a burnishing effect. The packing faces arepreferably somewhat rounded at the corners whereby to avoid sharp anglesand this feature, in conjunction with the smoothness of such faces,minimizes the liability of danger to the cavity walls or margins.

The packing faces formed at the ends of short sturdy shanlrs 2%. whosecross sectional outline conforms to the outline of saic faces and whichare provided at the ends of a suitably elongated handle body portion 4i.The shanks 3 preferably arranged contranngle in order that said facesmay be arranged close to the axis of the handle or body portion 4:,thereby to enable the most efficient application. of the force applied.

For mesial'cavities the p anes of the packing faces should form an ofapar mat-sly 40 or slightly less with a l touching the most .ad mncededge o plane and parallel to the 4E, and the k said axis of the handleshanks 8 by which said packing faces are carried are preferably arrangedwith their ares at angles of app oximately 90 to said i .ces. Theangular relation of the mesial packing faces to the line X in connectionwith the inclination at which the instrument is held, insures that thegingival portion ofthe filling shall be automatically condensedfirstfand with the most efiicient effect. The same angular relation ofthe packing; faces to the line X if applied to the instrument adaptedfor a distal cavity would have the least effect in the condensation ofthe amalgam upon the deep gingival margins. Accordingly the planes ofthe packing faces 1 and 2 for the distal cavities form reduced angle,approximately an angle of 25, with the line X, suchrreduced angleinsuring adequate condensation and adaptation of the to the vitalgingival margin.

In both cases, therefore, the packing faces arearranged in angularplanes best calculated to adapt them to the cavities, mesial distal. forwhich they may be intended.

lit has been found that for the larger torations the best condensationeffects achieved by packing faces 1 or 1, as "he case may be,of. 4mm.152mm. dimensions. Where the packing faces 1 or 1 are of suchdimensions. the correlative packing faces 2 or 2 should be of one-fourththe area of the faces 1 or l 2'. e. of X nomm. dimensions; For smallercavities the instruments while pcssessmg the features of structureLes-2,401

and arrangement above described, will have their working faces 1 or isomewhat smaller and their correlative working faces 2 or 2 aconsiderably smaller fraction of the area of the working faces 1 or 1,the preferred dimensions being 3mm. X 225mm. for the faces 1 or 1 and1mm. X .75mm. for the faces 2 or 2.

It will thus be seen that the relation of the areas of the correlativepacking faces is not the same in both cases and, therefore, may not beexpressed generically by a fraction. Accordingly the term correlative asapplied. to the packing faces is used in this description and in theappended claims to describe packing faces whose areas are in suchrelation that the larger face will be adapted to the final packing of acavity and the smaller face will be adapted to condensthe fillingmaterial into the undercuts and angles between the matrix and walls ofthe same cavity. The specification otherwise clearly indicates thedetails relation of these correlative packing faces in all necessaryinstances of their use. 7

Two instruments will, therefore, serve for all. mesial cavities. Twoothers, duplicates,

except for the modification of the angle'of the planes of the packingfaces and of the arrangement of the longer sides of the said facesposteriorly will. serve for all distal cavities, and will complete theseries. The four instruments ofthe series may be appropriatelydistinguished from one by suitable marking. lhus, as showndiagrammatically in Fig. 11, the instrument with the faces for mesialcavities may marked with the indicia hP-lVl and the instrument with thesmaller faces for mesial cavities may be marked Wi -dil while the twoinstruments distal cavities may in like manner, as showndiagrammatically in k 12, be marked D D -and D -D respe tively, theletter indicating mesial or distal and the numbers giving the largestface dimensions of the respective working terminals. 7

tial packing of its undercuts and matrix.

fully described my invention claim I 1. An instrument terial intoocclusal having correlative larger and smaller trapezoidal packingfaces, each of whose'greater for packing fillingmapester1or-teetli-cavities,

another dimensions is transverse and whose dimensional ratio is 4:3.

2. An instrument for packing filling material into occlusalposterior-teeth-cavities, having a smooth, plane trapezoidal packingface whose dimensional ratio is 4:3 and whose corners are rounded.

3. An instrument for packing filling material into occlusalposterior-teeth-cavities, having a smooth plane trapezoidal packing facewhose greater dimension is transverse and whose dimensional ratio is 4.An instrument for packing filling material into occlusalposterior-teeth-cavities, having correlative larger and smaller smooth,plane trapezoidal packing faces and an elongated handle or body portionprovided at its ends with shanks upon which said packing faces areformed. v

5. An instrument for packing filling material into occlusalposterior-teeth-cavities, having correlative larger and smaller smooth,plane trapezoidal packing faces and an elongated handle or body portionprovided at its ends with shanks upon which said packing faces areformed, said packing faces having their planes disposed at the sameangles to lines touching their most advanced edges and parallel to theaxis of said handle or body portion and said angles being correlated tosaid faces to insure that they will first act with full effect upon theportion of the filling adjacent the gingival margins of the cavity.

6. An instrument for packing filling ma terial into occlusalposterior-teeth-cavities, provided with correlative larger and smallersmooth, plane packing faces, each having similarly disposed longer andshorter transverse edges, and an elongated handle or body portionprovided at its ends with shanks upon which said packing faces areformed, said packing faces having their planes disposed at the sameangles to lines touching their most advanced edges and parallel to theaxis of said handle or body portion and also having their planes wherebythey will first act with full effect upon the portion of the fillingadjacent the gingival margins of the cavity.

In testimony whereof I have hereunto set my hand in the presence of twosubscribing witnesses.

DANIEL ANTON ZURBRIGG.

l Vitnesses:

W. G. SAMMoNs, W. S. DAUGHERTY.

